Author: pnorman
[Added to the original trac issue at 7.40am, Tuesday, 17th December 2013]

It is correct to encode the & in URLs as &

Author: colin.smale[at]xs4all.nl
[Added to the original trac issue at 9.28am, Tuesday, 17th December 2013]

Replying to [comment:1 pnorman]:

It is correct to encode the & in URLs as &

I am not so sure that that is always true ...

It will depend on whether XHTML or legacy HTML is being used, and apparently sometimes on the browser as well according to this article from 2008:
http://stackoverflow.com/questions/275150/xhtml-and-ampersand-encoding

Author: Jonathan Bennett
[Added to the original trac issue at 10.32am, Tuesday, 17th December 2013]

Replying to [comment:2 colin.smale@]:

I am not so sure that that is always true ...

Yes, it is, and the very article you reference points this out and explains the most common mistake of pasting an HTML encoded link directly into a browser's address bar:

"The encoding of & as & is required in HTML, not in the link. When the browser sees the & in the HTML source for a link it will interpret it as an ampersand and the link target will be as intended. If you paste a URL into your browser address bar it does not expect it to be HTML and does not try to interpret any HTML encoding that it may contain. This is why your example links that you suggest we should copy/paste into a browser don't work and why we wouldn't expect them to work."

Author: TomH
[Added to the original trac issue at 10.39am, Tuesday, 17th December 2013]

Just to add to which, when you select "Link" in the share tab we do not encode the ampersand, but when you select "HTML" to get an HTML fragment we do encode it. All of which sounds correct to me.

Author: aseerel4c26
[Added to the original trac issue at 11.03am, Tuesday, 17th December 2013]

this is a duplicate of ticket #4949

Author: colin.smale[at]xs4all.nl
[Added to the original trac issue at 11.06am, Tuesday, 17th December 2013]

Replying to [comment:3 Jonathan Bennett]:

Replying to [comment:2 colin.smale@]:

I am not so sure that that is always true ...

Yes, it is, and the very article you reference points this out and explains the most common mistake of pasting an HTML encoded link directly into a browser's address bar:

"The encoding of & as & is required in HTML, not in the link. When the browser sees the & in the HTML source for a link it will interpret it as an ampersand and the link target will be as intended. If you paste a URL into your browser address bar it does not expect it to be HTML and does not try to interpret any HTML encoding that it may contain. This is why your example links that you suggest we should copy/paste into a browser don't work and why we wouldn't expect them to work."

I stand entirely corrected. Having read the standards again it seems that accepting a bare "&" was strictly a non-compliance and everybody should have been using "&" in the first place.